Method for producing an anatomical prosthesis by computer-aided three-dimensional design

Description

DOMAINE TECHNIQUE DE L'INVENTION

[0001] The invention relates, in general, to the technical field of anatomical prostheses intended to repair, restore or re-establish anatomical parts for patients who have lost a limb or part of their body in order to give them back a so-called normal human appearance.

[0002] It also concerns the production processes of anatomical prostheses made of soft synthetic or composite material with soft and rigid parts.

[0003] The invention applies, in particular, to epitheses, facial prostheses, maxillofacial prostheses, and external breast prostheses to be inserted into a pocket of underwear or to be attached directly, for example, by medical adhesive or self-adhesive sheets, to the skin after complete healing following a total or partial mastectomy. ÉTAT DE LA TECHNIQUE ANTÉRIEURE

[0004] Synthetic prostheses are known and are generally provided after mutilation or surgical removal following accidents or in cases of invasive cancer requiring extensive or limited excision. Indeed, in these situations, patients need a prosthesis to replace the removed anatomical part in order to regain their physical integrity and an appearance as close as possible to their pre-existing state, thus enabling them to resume a normal social life.

[0005] The process involves replacing anatomical parts removed as a result of any circumstance requiring the prescription of an anatomical prosthesis, for example following cancer, trauma, for severe burns, following congenital diseases, or following mutilations resulting from assaults, attacks and for war victims, with a custom-made prosthesis most often made of silicone.

[0006] In France, 20,000 women, and worldwide, 720,000 women, undergo major surgical procedures each year with irreversible consequences following a diagnosis of invasive breast cancer. These cancers most often require the removal of one or sometimes both breasts, known as a mastectomy. In some cases, the removal is limited to a specific area where a tumor has developed. This area is most often located behind the nipple. This limited surgical procedure is called a lumpectomy. The psychological impact of these mutilations severely affects patients, and they may seek various techniques to regain their pre-surgical appearance and resume a normal social life.

[0007] Sometimes, reconstructive surgery will be performed, but for example, in the case of a partial mastectomy or lumpectomy, the original breast volume can be restored, but neither the nipple nor the areola, which are important parts of a breast's appearance, will be. Some patients refuse reconstruction, or it may not be medically possible.

[0008] Standard prostheses are available in various predetermined sizes and colors within a standard range. Because these prostheses are standard, they will never be an exact match to the patient's anatomy before surgery. Furthermore, these standard prostheses are designed exclusively to be inserted into a pocket of underwear specifically designed for this purpose.

[0009] In order for as many patients as possible who have undergone mutilation or surgical excision, such as a mastectomy, to be able to rebuild themselves psychologically and physically following this trauma, there is a need for a breast prosthesis, or other prosthesis, that perfectly replicates the removed anatomical part to replace it, but that is affordable for the majority of patients. To this end, a process for producing anatomical prostheses identical to the removed anatomical part is necessary to replace existing standard prostheses.

[0010] Patent application DE102018006839 A1 discloses a method for creating a prosthesis from digital scans of the body part to be removed before and after surgery. These pre- and postoperative digital scans are obtained from DICOM files generated using standard medical imaging techniques, such as mammography, sonography, tomography, magnetic resonance imaging (MRI), and CT scans. These DICOM files are part of the patient's medical record and were created by medical teams before and after the surgery. The DICOM files are then converted into STL files for use by a 3D printer. The accuracy of the files obtained using medical imaging techniques is insufficient for achieving a good visual representation of the prosthesis.This document does not show either a first digital volumetric survey obtained by three-dimensional digitization carried out by three-dimensional surface scanning of an envelope of the volume of at least one part of a patient's body before removal of an anatomical part to be replaced by said anatomical prosthesis, or a second digital volumetric survey obtained by three-dimensional digitization carried out by three-dimensional surface scanning of an envelope of the volume of the same said at least one part of the patient's body after removal of the anatomical part to be replaced by said anatomical prosthesis.

[0011] The present invention aims to remedy all or part of the drawbacks of the prior art by proposing in particular to use and exploit current technologies of three-dimensional scanning, computer-aided 3D design, and 3D printing to form a chain of digital technologies to produce prostheses personalized to each patient, in order to reproduce their original morphology.

[0012] To this end, it is proposed, according to a first aspect of the invention, a method for modeling an anatomical prosthesis by three-dimensional computer-aided design as defined in claims 1 and 2.

[0013] According to a second aspect of the invention, a method for producing an anatomical prosthesis made of flexible synthetic material is proposed by computer-aided three-dimensional design as defined in claims 3 to 11.

[0014] According to a third aspect of the invention, a computer program product as defined in claim 12 is proposed.

[0015] According to a fourth aspect of the invention, a computer-readable data carrier is proposed, on which the computer program product is recorded.

[0016] According to a fifth aspect of the invention, a signal from a data carrier is proposed, carrying the computer program product.

[0017] Other features and advantages of the invention are highlighted by the following description of non-limiting examples of implementation of the various aspects of the invention. BRÈVE DESCRIPTION DES FIGURES

[0018] The description refers to the attached figures, which are also given as non-limiting examples of embodiments of the invention: There figure 1a shows a representation of a part of a patient's body before a mastectomy; The figure 1b shows a representation of a part of a patient's body after a mastectomy; The figure 1c shows a representation of a volumetric scan prior to mastectomy; The figure 2a illustrates the device allowing the superimposition of volumetric scans before and after mastectomy; The figure 2b illustrates the tomographic scan of the breast to be removed; The figure 3 illustrates an initial method for producing anatomical prostheses; The figure 4 shows a cross-sectional view of a breast prosthesis according to a first embodiment; The figure 5 illustrates a second method of producing the anatomical prosthesis; The figure 6 shows a cross-sectional view of a breast prosthesis according to a second embodiment; The figure 7 shows a temporary breast prosthesis; The figure 7 shows a nipple and areolar prosthesis; and The figure 9 shows a full-coverage breast prosthesis.

[0019] For clarity, identical or similar elements are identified by identical reference symbols across all figures. DESCRIPTION DÉTAILLÉE D'UN MODE DE RÉALISATION

[0020] In the following description, the invention will be described primarily with reference to breast prostheses delivered after a total or partial mastectomy of one or both breasts. However, the principles and techniques implemented and described below apply mutatis mutandis to any type of prosthesis in the situations indicated above. Thus, the invention can also be applied to limb replacement prostheses after amputation, epitheses, facial prostheses, and maxillofacial prostheses.

[0021] The solution proposed by the invention consists of representing and reproducing identically the anatomical part that is removed, for example, a breast after a mastectomy, in order to replace it. Beyond the technical aspects of the procedures involved in manufacturing such an anatomical prosthesis, certain steps also aim to listen to and understand the trauma experienced by patients.

[0022] As depicted in the Figure 1a [Fig. 1a The anatomical prosthesis production process begins with an initial three-dimensional surface scan of the area of ​​the patient's body containing the anatomical part to be removed, in this case, a breast. This initial three-dimensional surface scan takes place during a first appointment with the patient at the prosthetist's office, during which various prosthesis options are presented using computer-generated images based on the initial three-dimensional surface scan. These images may include simulations of temporary and permanent prostheses. This three-dimensional surface scan is performed using a 3D surface scanner or any other three-dimensional scanning technique that converts the scanned anatomical volumes into a digital file.After the surgical procedure, in the example of implementation of the invention described below, a mastectomy, a new procedure is carried out to perform a second three-dimensional surface survey.

[0023] A three-dimensional surface scanner, or 3D scanner, allows for 3D scans using a technique that captures the shape of an object or anatomical part. The result is a 3D computer file that can be saved, edited, and even 3D printed. Several technologies enable 3D scanning of objects, environments, or people. The 3D scanner analyzes an object and produces a point cloud of its surface to digitize its outer shell, that is, its volume. This 3D scan is then processed by 3D software to obtain a precise reproduction of the scanned object. Most 3D scanners use laser triangulation technology or structured light.

[0024] The data resulting from a 3D scan, that is, the coordinates of the measured points within the object's volume, are stored in a file in STL, OBJ, PLY, etc. format. Non-contact 3D scanners represent a non-invasive technical solution for accurately recording anatomical parts of the body without altering the tissues, thus capturing the exact shape of the volume of the scanned anatomical part in digital form. Furthermore, these digital files can be easily converted to ultimately produce a 3D print of the scanned object or anatomical part.

[0025] Examples of 3D surface scanners usable for the applications described below include structured light scanners such as those from ARTEC (ARTEC EVA - LEO and SPIDER). Smartphone or tablet scanners can also be used. They all allow for recording the volume envelope of the scanned anatomical part and outputting an STL, OBJ, or PLY file. These digital files model an anatomical volume as needed, enabling various digital processing methods such as enrichment with additional data or 3D printing. During the initial consultation with the patient before the mastectomy, a skin color analysis of the breast to be replaced by the anatomical prosthesis is performed in addition to the initial three-dimensional scan. This skin color analysis is carried out using, for example, a spectrophotometer, such as a Spectroshade®, or a colorimeter, such as a Datacolor Coloreader EZ®.This color analysis allows for skin color measurements to be taken, recording the skin tones of the anatomical area to be removed so that the anatomical prosthesis can faithfully reproduce them. At this time, centimeter-level photographic measurements are also taken to record all visible details on the surface of the breast to be removed, such as freckles, veins, etc.

[0026] As illustrated by the figure 1a [Fig. 1a Whenever possible, an initial digital volumetric scan of an upper part of patient 1's body is performed, optionally with the other colorimetric and photographic measurements indicated above. The objective of this initial digital volumetric scan is to obtain a three-dimensional image of the volume envelope of the anatomical parts using a 3D surface scanner in order to reproduce the anatomical volumes identically before any transformation of this part of patient 1's body following a mastectomy.

[0027] The first step involves creating an initial 3D digital scan of at least one part of the patient's body to record all the anatomical details existing before the mastectomy. This initial 3D digital scan allows for the creation of the first digital volumetric scan. In the case of a breast mastectomy, the digital volumetric scan represents the digital transcription of the exact volumetric envelope of the breast with an accuracy of approximately 100 microns. Thus, the exact volumes of the patient's areola and nipple will be recorded in order to methodically reproduce the actual volumes that an anatomical prosthesis, in this case a breast prosthesis, must replicate.

[0028] There figure 1b [Fig. 1b This illustrates a second phase of the process that takes place after the mastectomy. During a second appointment with the patient at the prosthetist's office after the mastectomy, a second three-dimensional surface scan of the same upper body part of patient 1 is performed. This second three-dimensional surface scan is carried out using the same technique as the first and allows for the creation of a second 3D digital impression of patient 1's upper body after the mastectomy in the form of a second digital volume scan. The objective of this second three-dimensional surface scan is to obtain a three-dimensional digitization of the body volume envelope after the mastectomy. In particular, the second digital volume scan records the topography of the part of the patient's body that underwent the mastectomy and contains a scar resulting from the mastectomy.

[0029] Next, as illustrated in the figure 1c [Fig. 1c The first and second digital volumetric scans 3 and 4 are superimposed by digitally matching the two files. This produces, through transparency, a digital volumetric representation 5 of the volume envelope of the removed anatomical part that must be replaced by the anatomical prosthesis. Thus, the anatomical prosthesis to be designed can be generated using computer-aided three-dimensional design software that formalizes the volume envelope of the anatomical part missing following the surgical procedure. This three-dimensional CAD software uses the files of the first and second digital volumetric scans 3 and 4 to transpose the data contained in these files representing the scanned volumes to obtain the digital volumetric representation 5 illustrated in the diagram. figure 1c [Fig. 1c ] on the basis of which the envelope of the volume of a 3D anatomical part can be drawn and its volumes reproduced by 3D printer as described below.

[0030] To allow the superimposition of the first and second digital volumetric scans 3 and 4 and their processing by the three-dimensional CAD software mentioned above, positioning reference points must be established by the pre- and post-operative three-dimensional volumetric scans. One possible solution to ensure this positioning of the two consecutive scans is illustrated in the figure 2a [Fig. 2a In this solution, the first and second digital volumetric scans 3 and 4 are performed with markers positioned on the upper part of the patient's body 1, on which the three-dimensional volumetric scans are performed. In this example of an implementation of this part of the invention, these markers are placed on the patient before proceeding with the first and second digital volumetric scans 3 and 4. They take the form, for example, of a headband 20, a necklace 21, and a belt 22. Each of these markers has static markers 23. For example, the headband and the necklace each have three static markers 23, and the belt has five.These static markers 23 allow a perfect superposition of the first and second digital volumetric survey 3 and 4 and the processing of the corresponding files by the three-dimensional CAD software makes it possible to obtain the digital volumetric representation 5 which reproduces with a very high level of precision the anatomical part removed which the anatomical prosthesis must replace.

[0031] As illustrated in the figure 2b [Fig. 2b A computed tomography (CT) scan 24 performed before the mastectomy is also taken into account in the method of the invention to obtain an even more faithful reproduction of the anatomical part to be replaced by the anatomical prosthesis. The CT scan 24 is performed, for example, with a computed tomography scanner or by MRI (Magnetic Resonance Imaging). Preferably, this CT scan 24 will be processed by densitometric transmission software to obtain a digital tomographic scan 25. Thanks to this digital tomographic scan 25, the distribution of tissue density in the breast to be removed is reproduced identically in the anatomical prosthesis intended to replace it after the mastectomy. Advantageously, the CT scan 24 is performed during the first appointment with the patient using the landmarks 20 to 22 illustrated in Figure 1. figure 2a [Fig. 2a ] positioned on part of patient 1's body.

[0032] In certain specific cases, for example when the preliminary phase of pre-operative three-dimensional surveying illustrated in the figure 1a [Fig. 1a If a digital volumetric scan could not be performed, or in cases of bilateral mastectomy, it is possible to simulate the volume envelope formed by the patient's morphology before the mastectomy. In the case of unilateral mastectomy, a three-dimensional volumetric file of the patient's anatomy before the mastectomy can be created by symmetrically transcribing the volume envelope of the part of the patient's anatomy not affected by the mastectomy. This three-dimensional file obtained through symmetry can be used instead of the first digital volumetric scan. In the case of bilateral mastectomy, a three-dimensional volumetric file of the patient's anatomy before the mastectomy can be created based on a set of pre-recorded standard measurements corresponding to the volume envelope of the patient's morphology.In this situation, the three-dimensional file obtained by virtual reconstruction on the basis of standard measurements is used instead of the first digital volumetric survey 3 after validation by the patient.

[0033] Alternatively, it is possible to superimpose standard volumetric representations 5 with the second digital volumetric scan 4 of the patient in order to define the digital volumetric representation that best corresponds to the patient's anatomy, and after "matching" the corresponding digital files, to formalize by computer-aided 3D design prostheses appropriate to the patient's anatomy without using the first digital volumetric scan 3. In the case of the removal of a single breast without the first digital volumetric scan 3 having been able to be carried out, the digital volumetric representation 5 of the anatomical prosthesis to be made is carried out by 3D CAD on the basis of the breast not removed.Thus the process of the invention makes it possible to understand all the situations and challenges of postoperative reconstruction by external prosthesis and can also be applied to situations in which the first digital volumetric survey cannot be carried out, for example in cases of accidental mutilation.

[0034] As indicated above, in the production process of anatomical prostheses described, here breast prostheses, the various digital files resulting from the different measurements taken on the patient before and after the surgical procedure are transposed and formatted to allow additive manufacturing, also called 3D printing, according for example an SLA, FDM or SLS process, of a mold or directly of the anatomical prosthesis whether it is temporary, prototype or definitive as explained below.

[0035] There figure 3 [Fig. 3 Figure 30 shows a mold and its construction. In this first example of anatomical prosthesis manufacturing, the digital file corresponding to the digital volumetric representation 5 is transposed and formatted for use by a 3D printer to produce, through additive manufacturing, a mold into which the flexible synthetic material constituting the anatomical prosthesis, for example, biomedical-grade silicone, will be injected. The mechanical properties required for mold 30 necessitate the use of rigid synthetic materials such as ABS, PLA, PP, nylon, etc. To achieve this, mold 30 can be obtained using one of three types of 3D printing: FDM, SLA, or SLS.

[0036] The production of anatomical prostheses by injecting biomedical-grade silicone into a mold 30, obtained by 3D printing from a digital volumetric representation 5, allows for the creation of an anatomical prosthesis that perfectly replicates the removed anatomical part. The silicone injected or poured into the mold 30 will be colored throughout to faithfully reproduce the skin tone of the removed anatomical part, based on the digital colorimetric scan performed on the patient.

[0037] The mold 30 can be made in two parts, a base 31 and an injection volume 32, to produce an anatomical prosthesis in poured or injected silicone into the mold 30. In this case, the density of the anatomical prosthesis will be defined from the digital tomographic scan 25. The density of the anatomical prosthesis can be defined as the average density of the densities recorded in the digital tomographic scan 25.

[0038] There figure 3 [Fig. 3 ] represents a mold 30 in addition to two parts that allow the production of a multi-density silicone anatomical prosthesis. As explained above, the mold 30 has a mold base 31 on which is formed, in a protrusion, an impression of the scar 33 which faithfully represents the topography of the area of ​​the patient's body in which the scar 6 is located, as digitized in the digital volumetric representation 5 from the second digital volumetric scan 4 carried out after the mastectomy on the patient's body part 1. Thus, as illustrated by the figure 4 , a multi-density molded anatomical prosthesis 40 has a molded base 41 intended to be placed in contact with the patient's skin and to closely follow the topography of the area containing the scar 6 after the time required for complete postoperative healing and after the end of radiotherapy or chemotherapy following the mastectomy.

[0039] The multi-density molded anatomical prosthesis 40 comprises different zones into which silicones of different structures have been injected into the mold 30 according to the densities transposed from the digital tomographic scan 25. The multi-density molded anatomical prosthesis 40 illustrated in the figure 4 [Fig.4 ] includes a lower zone 42 on which the imprint of the scar 33 on the base of the mold 31 will have reproduced in negative the topography of the area of ​​the patient's body in which the scar is located 6. The multi-density molded anatomical prosthesis 40 also includes an internal zone 43, an areolar zone 44 and a nipple zone 45. Each of these zones 41 to 45 of the multi-density molded anatomical prosthesis 40 has a specific density determined from the density of the respective area of ​​the breast that was removed from the sensitometric measurements recorded in the digital tomographic scan 25.

[0040] To produce the multi-density molded anatomical prosthesis 40, a mold 30 is used in which an inner mold portion 34 can be positioned on the base of the mold 31. In this case, several inner mold portions 34 are required to obtain a multi-density molded anatomical prosthesis 40. For example, to produce the multi-density molded anatomical prosthesis 40 shown in the figure 4 [Fig. 4 We begin by positioning a first inner mold part 34, leaving only the volume corresponding to the nipple area 45 free within the mold volume 32. A silicone with the density of the nipple area will be injected into this area. In a second step, the first inner mold part 34 is replaced by a second inner mold part whose shape allows the injection of silicone with a density corresponding to the density of the areolar area 44, thus creating the areolar area 44. A third inner mold part allows the injection of silicone with the desired density to create the inner area 43. The lower area 42 is created last, without inserting an inner mold part 34.

[0041] After fabrication of the molded anatomical prosthesis, whether single-density or multi-density (40), a finishing step can be performed by applying a final coating agent to reproduce all the external details recorded in the centimeter-scale photographic survey. The coating agent used for this finishing step may be a medical-grade silicone with various extrinsic pigments, applied, for example, with an airbrush or a brush.

[0042] There figure 5 [Fig. 5 This illustrates the different stages of producing a 3D-printed anatomical prosthesis, preferably using SLA or FDM 3D printing as shown here. The anatomical prosthesis can be obtained directly by 3D printing by formatting the digital representation file so that a 3D printer can create an anatomical prosthesis that perfectly replicates the volume of the removed anatomical part. The biomedical silicone used for this purpose can be dyed throughout using digital colorimetry so that the anatomical prosthesis also matches the patient's skin tone.

[0043] Due to the complexity of the shape of the anatomical prosthesis, FDM or SLA 3D printing is particularly suitable for the manufacture of anatomical prostheses, especially SLA 3D printing because a printed base 61 may have to represent in negative the topography of the area of ​​the patient's body in which the scar 6 is located as digitized in the digital volumetric representation 5.

[0044] 3D printing allows for the creation of both single-density and multi-density anatomical prostheses by varying the internal structure of the anatomical prosthesis according to the data from the digital tomographic scan. The internal structure of the prosthesis can take different forms. figure 5 This shows an anatomical prosthesis being printed, exhibiting a lattice structure 62. The printed base 61 of the anatomical prosthesis rests on a print bed 50 of a 3D printer 51, for example, an FDM type, on which a print base (not shown) is positioned. This base can represent the topography of the scar site 6, and the volume of the anatomical prosthesis 60 will be printed on it. The print head 52 delivers the filament, which is melted to the locations where the material must be deposited layer by layer on the print bed 50.

[0045] There figure 6 [Fig. 6 Figure 60 shows a cross-section of a 3D-printed anatomical prosthesis. The internal structure features a lattice 62 produced by 3D printing, the structure of which allows for the reproduction of the various density measurements recorded in the digital tomographic scan. A peripheral structure 63 reproduces the skin tone recorded in the digital colorimetric scan 25, as well as the peripheral density of the removed anatomical area. The same applies to an areolar area 64 and a nipple area 65. The printed base 61 reproduces in negative the topography of the patient's anatomical area, including the scar 6, so that the printed base closely conforms to the shape of the patient's scar 6.

[0046] 3D printing allows for the direct creation of a 60-page anatomical prosthesis that perfectly replicates all the external and internal details of the removed breast, including those recorded during the centimeter-precise photographic survey. Optionally, the external details recorded in the centimeter-precise photographic survey can be reproduced during a finishing stage, which can be performed manually using, for example, an airbrush spraying tinted biomedical-grade silicones to reproduce these external details, or a brush.

[0047] For example, when the patient can tolerate a so-called definitive anatomical prosthesis, such as the printed anatomical prosthesis 60 described above, this prosthesis can be printed very realistically, identical to the anatomical part whose shape was digitized in the digital volumetric representation 5. The process of the invention then makes it possible to generate contour joints 66 allowing the prosthesis to be applied very intimately to the patient's body in order to render its contours virtually invisible thanks to the custom color and texture of the printed anatomical prosthesis 60. The process of obtaining an anatomical prosthesis by molding described above also makes it possible to obtain a definitive prosthesis of this type.

[0048] Thus, the implementation methods of the invention described above make it possible to reproduce the volume, skin, complexion, and density of the breast using 3D printing. Indeed, the internal masses measured by body densitometry will be transposed by software to represent the data recorded inside the breast before its removal, or of the contralateral breast when necessary.

[0049] Before fabricating the final anatomical prosthesis described above, it may be advisable to produce a silicone or resin prototype to validate the prosthesis volume after visualizing a representative volume. The finishing stage with the coating agent and the final fitting on the patient to refine all possible features, particularly the contour seal, can thus be carried out during or after validation of the anatomical prosthesis shape. Visualizing and validating a prototype anatomical prosthesis is particularly important when the initial digital volumetric scan could not be performed before the mastectomy.

[0050] Before being able to benefit from a definitive anatomical printed or molded prosthesis, a temporary prosthesis is offered to patients in the healing phase and during postoperative treatments by radiotherapy or chemotherapy during which patients cannot tolerate contact of the prosthesis with the skin.

[0051] However, to enable these patients to quickly benefit from a custom-made prosthesis tailored to their anatomy after mastectomy, the methods for implementing the invention make it possible to produce realistic, temporary anatomical prostheses adapted to the patient's morphology, but usable in bras instead of being glued directly to the patient's skin with medical adhesive. These temporary prostheses are designed to fit into a fabric pocket provided for this purpose in the patient's underwear. This temporary solution allows patients to benefit from the technology described above and thus preserve their own anatomy, unlike current standard solutions that do not perfectly reproduce the patient's anatomy.

[0052] During the healing phase or during radiotherapy and chemotherapy treatments, patients will have no problem tolerating these temporary anatomical prostheses while waiting to be able to tolerate the definitive anatomical prosthesis intimately positioned on the skin and which can be glued by a biomedical adhesive or a self-adhesive sheet for holding the prosthesis directly on the patient's body.

[0053] There figure 7 [Fig. 7 ] shows a provisional anatomical prosthesis 70 produced by molding or 3D printing as described above and illustrated in figures 3 And 5This temporary anatomical prosthesis, size 70, is designed to be placed in an underwear pocket for wear, particularly during the months following a mastectomy. The temporary anatomical prosthesis, size 70, is generally provided approximately two months after the mastectomy. It can therefore be made as a temporary model while awaiting complete postoperative healing, or while awaiting reconstruction with an internal prosthesis. The temporary anatomical prosthesis, size 70, can also serve as a prototype for the final anatomical prosthesis.

[0054] First, a pattern 71 is selected, for example, based on the digital volumetric representation 5, from among the virtual patterns corresponding to the different existing breast sizes. Then, a temporary prosthesis volume 72, formalized by the digital volumetric representation 5, is digitally merged with pattern 71. The result of this digital file merging serves as the basis for the creation of the temporary anatomical prosthesis 70 by molding or directly by 3D printing.

[0055] The temporary anatomical prosthesis 70 is worn in a suitable bra. The volume of the temporary prosthesis 72 is not in direct contact with the patient's skin, as it is the pattern 71 that will be against the skin inside the bra. Thus, the topography of the base of the volume of the temporary prosthesis 72 does not need to be adapted to the shape of the scar 6. The volume of the temporary prosthesis 72 is injected or molded from a biomedical-grade silicone with a single density corresponding to the average density of the removed breast tissue for each patient, or a multi-density material corresponding to the data from the digital tomographic scan 25.

[0056] Similarly, the skin tone of the temporary anatomical prosthesis 70 is determined by the shade of the silicone injected or poured into the mold 30, or used for 3D printing. This shade can be customized or selected from a range of colors representing common skin tones based on a digital colorimetric scan. A final coating agent can be applied to the volume of the temporary prosthesis 72 to finalize its external appearance.

[0057] Nowadays, advances in cancer diagnosis increasingly allow for the avoidance of total mastectomy, with partial mastectomy or lumpectomy, which generally involves the removal of the nipple and areola, being performed instead. Furthermore, advances in surgical techniques more frequently allow for reconstruction with an internal prosthesis, although the nipple is still missing. Consequently, nipple and areola reconstructions are increasingly in demand, as they are among the most important elements for the realism of all breast prostheses.

[0058] There figure 8 [Fig. 8 [This] shows a nipple and areola prosthesis 80, which is prescribed following a lumpectomy where the nipple and areola are removed, or in cases where they are missing following surgical reconstruction with an internal prosthesis after a mastectomy. Thus, the method according to the invention makes it possible to obtain, by molding or 3D printing, a nipple and areola prosthesis 80 conceptualized and formalized as described above, and to proceed with its conceptualization so that it can be integrated into the patient's remaining anatomy to identically reproduce her pre-operative anatomy.

[0059] There figure 9 [Fig. 9[Figure 90 shows a full-coverage breast prosthesis.] Following a partial mastectomy, for example, the removal of half a breast, or in the case of a total mastectomy followed by reconstruction with an internal prosthesis, the full-coverage breast prosthesis 90 may be prescribed. The full-coverage breast prosthesis 90 is made by molding or 3D printing according to the process of the invention described above in order to identically reproduce the removed half of the breast. An external surface 91 of the full-coverage breast prosthesis 90 identically reproduces the nipple, areola, and external details of the removed half of the breast using the digital tools described above. These tools also make it possible to create an internal surface 92 that will be in close contact with the remaining part of the breast and will conceal the scar 6. For this purpose, the internal surface 92 can reproduce in negative the topography of the area of ​​the breast containing the scar 6.

[0060] The invention thus makes it possible to produce anatomical prostheses, such as definitive or temporary breast prostheses, by reproducing them through direct 3D printing or by injection into a mold made by 3D printing. In both cases, the envelope of the volume obtained by 3D printing is identical to the envelope of the volume of the anatomical part to be removed, based on a digital volumetric representation 5 of the volume of the anatomical part to be replaced by the anatomical prosthesis 2. This digital volumetric representation 5 is obtained by 3D CAD by superimposing a first digital volumetric scan 3 carried out before the surgical procedure or a 3D simulation of the patient's body part before the surgical procedure, and a second digital volumetric scan 4 carried out after the surgical procedure.

[0061] To further enhance the tactile realism of the anatomical prosthesis 2, particularly when it is a definitive prosthesis, the density distribution within the anatomical prosthesis 2 or its internal structure is reproduced from the digital tomographic scan 25. The same applies to the visual realism of the anatomical prosthesis 2, which can be improved by reproducing the patient's skin tone from the colorimetric scan and / or the centimeter-scale photographic scan of the anatomical part to be removed. The various digital data sets from the tomographic scan, the colorimetric scan, and / or the centimeter-scale photographic scan can supplement the initial volumetric digital scan 3 or the volumetric representation 5.

[0062] The development of different methods of producing anatomical prostheses aims to physiologically and psychologically repair amputee or mutilated patients, particularly patients who have undergone a mastectomy or lumpectomy following breast cancer.

[0063] As indicated in the preceding description, the various aspects of the invention can be implemented to produce prostheses other than breast prostheses without departing from the scope of the invention. For example, the method of the invention makes it possible to produce an epithesis to replace a nose or an ear that reproduces identically, or at least realistically if the mutilated part could not be scanned beforehand, the density of the tissues that compose it as well as the cartilaginous parts. According to another example, the method of the invention makes it possible to reproduce an amputated limb identically by manipulating the molded or injected materials, in particular their densities and rigidities. Thus, the anatomical prosthesis will faithfully reproduce the volumes reproducing the muscles as well as those reproducing the skeleton of the amputated limb.

[0064] Naturally, the invention described above is by way of example. It is understood that a person skilled in the art is capable of carrying out different embodiments of the invention and implementing it for other purposes.

Claims

1. Method for modelling an anatomical prosthesis (2) via computer-aided three-dimensional design, comprising the following steps: - obtaining first data regarding a digital volume representation (5) of an envelope of the volume of the anatomical prosthesis by superposition: - of a first digital volume survey (3) obtained by three-dimensional digitization, said survey being taken via a three-dimensional surface scan of an envelope of the volume of at least one part of the body of a patient (1) before ablation of an anatomical part to be replaced by said anatomical prosthesis (2), or via digital simulation of the envelope of the volume of at least one part of the body of a patient (1) before ablation of an anatomical part to be replaced by said anatomical prosthesis (2), and - of a second digital volume survey (4) obtained by three-dimensional digitization, said survey being taken via a three-dimensional surface scan of an envelope of the volume of the same said at least one part of the body of the patient (1) after ablation of the anatomical part to be replaced by said anatomical prosthesis (2).

2. Method for modelling an anatomical prosthesis (2) via computer-aided three-dimensional design according to Claim 1, further comprising one or more of the following steps: - obtaining second data via a digital colorimetric survey and / or via a centimetre-scale photographic survey of said anatomical part before its ablation; and / or - obtaining third data via a digital tomographic survey (25) of said anatomical part before its ablation.

3. Method for producing an anatomical prosthesis made of flexible synthetic material via computer-aided three-dimensional design based on the method for modelling an anatomical prosthesis (2) according to either of Claims 1 and 2.

4. Method for producing an anatomical prosthesis made of flexible synthetic material via computer-aided three-dimensional design according to Claim 3, wherein the external visual appearance of the anatomical prosthesis (2) identically reproduces the visual appearance of the anatomical part to be replaced by said anatomical prosthesis (2) based on the second data; and / or - third data, said second data and / or third data complementing said first data.

5. Method for producing an anatomical prosthesis made of flexible synthetic material via computer-aided three-dimensional design according to either of Claims 3 and 4, wherein: - a base of said anatomical prosthesis oriented towards the skin of the patient is fused to a template (70) the size of which corresponds to that of said base of the anatomical prosthesis; or - a base (41; 61) of said anatomical prosthesis (2) intended to make contact with the skin of the patient has a topography obtained from said second digital volume survey (4) in order to correspond identically to the profile of a region of the body of the patient from which was removed the anatomical part to be replaced by said anatomical prosthesis (2).

6. Method for producing an anatomical prosthesis made of flexible synthetic material via computer-aided three-dimensional design according to any of Claims 3 to 5, wherein a mould (30) is produced based on said digital volume representation (5), into which mould the flexible synthetic material is injected to form said volume of said anatomical prosthesis (2).

7. Method for producing an anatomical prosthesis made of flexible synthetic material via computer-aided three-dimensional design according to Claim 6, wherein the mould (30) is produced by additive manufacturing from the digital volume representation (5).

8. Method for producing an anatomical prosthesis made of flexible synthetic material via computer-aided three-dimensional design according to either of Claims 6 and 7, wherein the flexible synthetic material injected into the mould (30) has: - a complexion corresponding to the digital colorimetric survey; and / or - a density corresponding to the average density of the digital tomographic survey (25), or a density distribution derived from the digital tomographic survey (25).

9. Method for producing an anatomical prosthesis made of flexible synthetic material via computer-aided three-dimensional design according to any one of Claims 3 to 8, wherein a finishing step makes it possible to reproduce, after moulding the anatomical prosthesis (2), the pigmentation of the various regions of the volume of said anatomical prosthesis (2) identically to the anatomical part to be replaced by the anatomical prosthesis (2) based on the digital colorimetric survey, and / or centimetre-scale photographic survey.

10. Method for producing an anatomical prosthesis made of flexible synthetic material via computer-aided three-dimensional design according to either of Claims 3 and 4, wherein the anatomical prosthesis (2) is produced by additive manufacturing based on: - said first data so that the shape of the volume of said anatomical prosthesis (2) is identical to the shape of the anatomical part to be replaced by said anatomical prosthesis (2); - said second data so that the visual appearance of said anatomical prosthesis (2) is identical to the visual appearance of the removed anatomical part; and / or - said third data so that the density distribution in said anatomical prosthesis (2) is identical to the density distribution in the anatomical part to be replaced by said digital prosthesis (2).

11. Method for producing an anatomical prosthesis made of flexible synthetic material via computer-aided three-dimensional design according to any of Claims 3 to 10, wherein the flexible synthetic material used is a biomedical silicone the bulk of which is tinted to reproduce the colours to the tone and saturation level required by the digital colorimetric survey.

12. Computer program product comprising instructions that, when they are executed by a computer, cause the computer to implement the method according to any of Claims 1 to 11.

13. Computer-readable data medium on which is recorded the computer program product according to Claim 12.

14. Signal of a data medium, carrying the computer program product according to Claim 12.

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